Grassland Habitat Group
1) Describe the habitat
(Billings 1988, Braun 1980, Brown and Chambers 1990, Hann 1990, Ives and Barry
1974, Thilenius 1975, Zwinger 1972):
a) Historic conditions: Because many alpine ranges have been used for summer grazing continuously since the mid to late 1800s, it is often difficult to determine what their “natural” state was. However, except for some shifts in vegetation composition as a result of grazing, and other obvious but local impacts from recreation and mining, alpine tundra/grasslands probably existed historically in a similar state that they do today.
b) Present
conditions: Impacts from human
developments, pollution, and disturbance to natural processes have been
relatively low in the alpine zones compared to other ecosystems. However, alpine tundra is sensitive to
disturbance, and the consequences are often highly visible. Because of the lack of buffering ability in
alpine ecosystems, the effects of human disturbances are more drastic and
long-lasting than in other more productive ecosystems. Impacts from disturbances such as mining and
recreation are usually obvious (e.g. rutting, erosion, and vegetation loss) but
occur on a local scale. While grazing is
much less intense than it was in the early 20th century, its impacts
(e.g. changes in vegetation composition, erosion, and soil compaction) often
occur on a landscape scale. Since alpine
tundra/grasslands make up less than 1% of the land area in
2) Identify the issues:
a) Use: Habitat for wildlife; grazing, especially by
sheep; recreation (e.g. hiking, hunting, fishing, photography, rock climbing,
camping, off-road vehicle travel, skiing, and horse-packing); and mining are
the major uses. In addition, alpine
areas are the primary watersheds for agricultural, industrial, and metropolitan
development as snow accumulation and water storage in these areas provide the
main sources of summer runoff for
b) Access: Most alpine tundra/grasslands (98.5%) are in public ownership, but a large proportion of these ecosystems is protected as wilderness (72%), which prohibits mechanized equipment and limits the range of recreational activities. Remoteness, rough terrain, and seasonal use have also discouraged exploitation, but difficulty does not preclude use and is attractive to many. Improved equipment like snowmobiles, all-terrain vehicles, snowboards, and cross-country skis; and an increase in paved roads have allowed increased access, especially in areas that are not designated as wilderness.
c) Problems: Incompatible livestock grazing; high intensity recreation (e.g. summer use of ski lifts, high density hiking and camping, and packstock can cause soil compaction, erosion, and vegetation loss); off-road vehicle travel (including snowmobiles which impact snow quality and wildlife mobility and distribution); road construction; mining, which may cause pollution and landscape damage; nonnative species (including mountain goats); acid rain, which strongly affects alpine areas because they have little buffering ability; and global warming, which threatens to reduce the extent of alpine tundra through encroachment of forest. Short, cool growing seasons, strong winds, frequent frosts, and a limited pool of adapted plant species limit successful revegetation of disturbances.
d) What has been the cause of change to the habitat: Impacts from human developments, pollution, and disturbances have been relatively low in the alpine tundra/grassland compared to other ecosystems. However, these areas are sensitive to disturbance by humans, and the consequences are often highly visible, at least locally, and very slow to regenerate. Primary human disturbances that have affected the alpine ecosystems include recreation, domestic livestock grazing, mining, road construction, and air pollution and associated global climatic change.
The intensity of recreation in alpine habitats is increasing. As hikers and pack animals have increased in number, casual trails and campsites through alpine vegetation have proliferated into extensive networks. As trail systems grow, many alpine plant species decrease in abundance, while semi-weedy species from lower elevations increase in numbers. Late-summer stored carbohydrates in vegetation within 1.5 feet (0.5 m) of the trail decreases by 20 to 50%, as compared with the amounts stored by plants of the same species just beyond 7 feet (2 m) from the trail. Other impacts of high intensity recreation include soil compaction and erosion.
Alpine
ranges have been used for grazing sheep since the mid to late 1800s. Early grazing operations herded sheep in
tightly grouped bands, continuously bedded in the same location for several
nights in a row, and drove sheep to and from water. These practices caused losses of forage
through trampling and overgrazing, especially near water; and soil damage from
excessive trailing and compaction. High
intensity grazing caused changes in vegetation composition (e.g. the
unpalatable alpine avens has probably increased because of grazing pressure on
more choice species). Sheep numbers
peaked in the western
Historically,
mining operations were on a smaller scale, but were far more extensive than
they are today. Because the alpine
ecosystem recovers so slowly, many mine sites are still evident even after more
than a century (including old roads, deserted structures, and mine
tailings). In localized communities that
have had impacts from mining there has been a loss in plant species diversity
and erosion along roads and trails.
Nearly 12% of the alpine habitats in the western
Road development in alpine habitats has brought more people, exotic plant species, and pollution into the ecosystem. Off-road vehicle travel, especially within reach of roads and towns, has caused significant damage to vegetation cover and soils. Even snowmobiles have impacts on snow quality and wildlife mobility and distribution.
Pollution is increasingly affecting the alpine tundra, primarily through acid rain, which strongly affects alpine areas because they have little buffering ability; and global warming, which threatens to reduce the extent of alpine tundra through encroachment of forest.
3) Priority
bird species in Alpine Tundra/Grassland habitat in
Level III:
Best
Management Practices
Land managers can take a variety of simple and inexpensive actions to improve alpine tundra/grasslands for birds and help them nest successfully. By maintaining and restoring habitat for birds in alpine habitat, many other wildlife species will also benefit. Some management activities may also improve watershed health by reducing soil erosion and increasing water retention.
As
a land manager, the actions you take will depend on your goals, resources, and
commitment, as well as the physical characteristics of the alpine tundra, such
as soil type, topography, existing vegetation, and microclimates. The following Best Management Practices
(BMPs) should provide some reasonable guidelines for managing alpine
tundra/grassland habitats to benefit a wide variety of resident and Neotropical
migratory birds in
Many of the Best Management Practices for alpine tundra/grasslands fall into major categories of land use such as Grazing, Recreation, etc. The recommended BMPs are broken out into categories for convenience, although some are general enough to cross into other categories.
Alpine
tundra/grasslands occupy high-mountain summits, slopes, and ridges above
timberline. In
Typical high-elevation growing seasons range from 45 to 90
days, with average summer temperatures near 50° F (10° C). Growing season temperatures frequently fall
below freezing, and frost occurs throughout the growing season in many
areas. Precipitation occurs mainly as
winter snow and may vary from 25 to over 47 inches (63 to over 120 cm)
annually, but soil water availability is highly variable with season, location,
and topography. For example, snowfields
commonly accumulate on the lee sides of ridges while ridgelines may remain
nearly snow free due to redistribution by wind.
Some alpine habitats may be up to 70% snow free in winter. High winds are common in alpine ecosystems,
and can cause significant soil erosion and be physically and physiologically
detrimental to plants. Also, wind coupled
with high solar radiation can promote extremely high rates of evaporation and
transpiration.
In a world of intense radiation, wind, cold, snow, and ice, alpine vegetation is close to the ground and consists mainly of perennial grasses, sedges, forbs, and low-growing shrubs with prominent inclusions of lichens and mosses. Compared to ecosystems at lower elevations, the alpine tundra contains few plant species; usually there are no more than 200 to 300 species present in the alpine zone of a given mountain range. Perennial herbs (including grasses, sedges, and low woody or semi-woody shrubs) dominate the alpine landscape; they have much more root and rhizome biomass than that of shoots, leaves, and flowers. The roots and rhizomes not only function in water and nutrient absorption but also play a very important role in over-winter carbohydrate storage. Annual plants are rare in this ecosystem and usually are only a few inches tall, with weak root systems.
Alpine
areas are unique because of the severity and complexity of their environmental
conditions. Very small changes in
topography [as small as 1 foot (0.3 m) or less] may mean the difference between
a windswept area or an area of snow accumulation, changing the potential
productivity and plant community drastically.
Between these extremes of drought versus saturation, several
intermediate environments may exist all within a few yards of each other,
depending on topography, substrate, and climate. Alpine vegetation generally occurs in a mosaic
of small patches with widely differing environmental conditions. Vegetation types vary from cushion and rosette
plants on the ridges and in the rock crannies; to herbaceous and grassy
vegetation along the slopes; dwarf shrubs with grasses and forbs below the
melting snowdrifts; and sedges, grasses, low shrubs, and mosses in the bogs and
along the brooks. The most prominent
plant community types in
Nowhere in
Because of the severe climate, few vertebrate species,
including birds, are able to breed in this habitat. Although the avifauna of the alpine tundra is
small compared to other habitats, these species are typically specialized and
endemic, and are not found in other habitats during the breeding season.
1) Conserve unique
representatives or core areas of alpine tundra/grasslands in
2) Identify and preserve
local sites that are important for the conservation of priority species
breeding in alpine tundra/grasslands.
3) Acquire a basic
knowledge of the ecology of alpine habitats in order to properly allocate the
various resources. Because of the steep,
rugged topography, high erosion potential of the soils, and the short growing
season, alpine ranges require careful management.
4) Regularly
monitor birds to see how the management plan is working, and redirect efforts
if necessary (with special emphasis for species that seem to be declining). Implement alpine habitat monitoring programs
to establish baseline data and identify changes in habitat quality (both
positive and negative) through time. Use
standardized methods to monitor the habitats and sensitive species in an area,
before and at several-year intervals after treatments are applied, to aid in
making proper land management decisions in the future.
5) Consider both long-
and short-term impacts and/or benefits of any activities within alpine
areas. Limit activities that degrade or
remove alpine habitats (e.g. heavy recreational use, overgrazing, and invasion
by exotic plants). Manage alpine
tundra/grasslands for sustainable use without abuse over the long-term.
6) In the use plans for alpine
habitats, pay considerable attention to the kinds of vegetation and soils
present and their susceptibility to change and destruction. Remember that most alpine vegetation returns
very slowly after destruction.
7) Manage for a variety
of locally native plants. Different
plant species host different insect populations, which provide food for a
variety of bird species.
8) Use minimum impact
fire suppression tactics (e.g. allow it to burn; and limit the use of
retardants, fire lines, etc.). Fire, an
important successional influence at lower elevations, is not usually
influential in the alpine zone. In
general, alpine communities are usually too wet to burn, or the plants are too
widely spaced to carry a fire. On the
other hand, diligent fire suppression tactics may cause lasting damage to the
local ecosystem.
Although grazing in alpine tundra/grasslands is limited by the short snow-free season and low productivity, and ecosystem recovery after disturbances is slow, proper stocking levels and grazing regimes can be compatible with alpine tundra/grassland maintenance and improvement. However, improper grazing practices in alpine areas can eliminate vegetation, cause soil erosion and compaction, encourage invasion of noxious plants, and cause changes in vegetation composition. The degraded condition of some alpine areas in the West is from uncontrolled grazing, mainly by sheep, that occurred in the late 19th and early 20th centuries; today’s successful manager can learn from past mistakes. The Best Management Practices for grazing focus on protecting alpine tundra/grasslands during crucial growing periods.
1) Because the ecology of the alpine zone is unique, carefully consider range management principles and practices developed in other ecosystems before extrapolating them into the alpine.
2) Grazing management plans for alpine tundra/grasslands should be developed and evaluated on a case-by-case basis by the managing agency or landowner because no single grazing strategy will fit all situations. Determine site-specific alpine area objectives and tailor the grazing management plan to help meet the objectives. Consider the site’s specific factors of concern; its potential and capability; its suitability for grazing livestock and the type of stock best suited to the area; and the ideal grazing strategy, including the time, place, amount, duration, and intensity of grazing. Monitor the effects of each grazing strategy on the alpine area to check progress toward the objectives. Record how key alpine plant species and the overall alpine tundra/grassland ecosystem respond to grazing management (annual photographs taken from the same point are helpful).
3) Maintain proper stocking rates and livestock distribution to protect alpine ecosystems. Incompatible grazing can have harmful long-term effects on survival and regeneration of vegetation; can negatively influence the species, structure, and health of alpine vegetation; and can cause soil compaction and erosion. Manage grazing intensity at a level that will maintain the composition, density, and vigor of desired plants and will not damage alpine soils.
4) Limit the amount of time livestock spend in alpine tundra/grasslands. This can be a significant factor in the condition of the alpine area. Base the length of the grazing period within an alpine zone on the areas livestock are actually using, not the entire allotment. If needed, add more rest to grazing cycles to increase plant vigor or encourage more desirable plant species composition.
5) Where feasible, use grazing systems like deferred-rotation, rest-rotation, high intensity-low frequency, and short duration to combine periods of use with nonuse. A year of rest for each alpine pasture every three to four years is beneficial for long-term alpine tundra/grassland maintenance.
6) Control the timing of grazing to keep livestock off alpine soils and vegetation when they are most vulnerable to damage (when the ground is saturated) and to coincide with the physiological needs of target plant species. Begin grazing in alpine areas in mid July or later to avoid grazing during the period of most active plant growth and to avoid the chance of trampling damage because of wet soils. Remove livestock from alpine areas by mid September to avoid trampling damage to soil that has been moistened by snow but it is not yet solidly frozen; to avoid damage to preformed flower buds, which could influence plant growth the following growing season; and to avoid livestock losses to early fall snowstorms.
7) Ensure adequate residual vegetation cover is left after grazing (70 to 80% of the herbage of the major species); this is essential for maintaining alpine ecosystem health. Instead of focusing on how much vegetation can be removed, focus on how much and what type of vegetation should be left.
8) Allow time for plants to rest and regrow between grazing periods to ensure they remain vigorous and productive. Plants that are continuously grazed during the growth period will lose their vigor and stop producing seeds, and their roots will die back, eventually causing a change in the plant community from more productive, palatable species to less productive and less palatable plants.
9) Improve livestock distribution and forage use by using salt and mineral blocks, but avoid placing them within or immediately adjacent to riparian, wetland, or aquatic areas [at least ½ mile (0.8 km) away].
10) Consider temporarily removing livestock from an area
that is damaged or otherwise needing protection. Livestock exclusion can be a short- or
long-term option for locally or regionally rare vegetation types, sites
undergoing restoration, wet sites (e.g. springs, seeps, wet meadows, streams,
and near melting snow banks), very dry sites (because of their low herbage
production and the high erosion potential), steep slopes (greater than 40°),
and other areas that are easily degraded.
11) Distribute sheep in loosely bunched bands and move them slowly, but steadily, in one direction while grazing (progressive herding). Herd bands of sheep by guiding the movement of the lead animals rather than herding from the rear. Plan herding so the band reaches water only once a day; graze the band quietly to water, rather than driving it. Graze a given area only one time during the grazing season, and do not allow the sheep to remain in the area long enough to cause excessive forage utilization. Bed the band down on a well-drained site near where they finish grazing, at a different location each night. Provide salt in movable containers on the bedding ground.
12) Avoid the repeated use of sheep driveways.
Wildlife, especially big game animals, can impact alpine tundra/grasslands. Managing for one species can sometimes have negative impacts on other species, such as birds. Wildlife management goals for each alpine area should be well planned, and should complement the overall goals of the alpine community.
1) Consider alpine tundra/grassland conditions and big game impacts when setting herd objective levels. Do not exceed the carrying capacity of alpine habitats.
2) Use whatever management techniques are available
to reduce the mountain goat herd in
Unfortunately for birds, people also like to use alpine areas and some recreational uses are not compatible with bird conservation goals. Recreational activities, such as camping, hiking, biking, horse-packing, and off-road travel, can degrade alpine tundra/grasslands. Recreationists may trample plants, compact the soil, increase soil erosion, and increase the incidence of weed invasion. Recreational use can affect birds by creating disturbance and habitat degradation, especially during the breeding season.
1) Consider potential disturbances to birds and habitat (and other wildlife) when planning or locating trails, camping sites, picnic areas, and other sites of human activity within alpine areas.
2) Locate new recreation sites outside of alpine areas wherever possible. If sites must be within alpine zones, concentrate them in one area, rather than spreading them throughout the alpine area, to limit negative impacts on breeding birds and habitat.
3) Keep pets under control in recreation areas. Free-roaming dogs can be devastating to birds that nest on or just above the ground.
4) Promote “Tread Lightly” recreation ethics. Educate outdoor enthusiasts about the unique and fragile nature of alpine habitats, the problems humans can cause and how they can avoid damaging these areas.
5) Manage or restrict off-road vehicles, bicycles, and horses in alpine tundra/grasslands because soil compaction and ruts caused by these uses can lead to erosion and long-term loss of soil and vegetation. Driving vehicles off-road across alpine habitats destroys vegetation and contributes to soil erosion and compaction. Keep all vehicles on established roads and trails or confined within areas established specifically for off-road recreation.
6) Reduce impacts to alpine areas by keeping hikers on established trails. In sensitive areas, hikers can damage vegetation and contribute to soil erosion.
7) Reduce recreational disturbances, including bird watching, in alpine areas during the bird nesting season, especially where rare, sensitive, or endangered species nest.
8) Limit scenic pullouts along highways in alpine
habitat. Scenic pullouts bring people to
a stop and encourage them to explore on foot, endangering the soils and
vegetation in the area. Post
interpretive signs at existing pullouts to educate the public about the unique
and fragile nature of alpine habitat.
9) Some of the heavily used alpine slopes have been
webbed with paths. In spite of
established trails, hikers in non-forested areas often take the shortest
distance between two points, or simply strike off on their own. Reestablish vegetation by reseeding and
replanting, blocking paths off, and covering them with mesh and burlap to
prevent erosion. It is necessary to
restore their original aspect since any trace of a path is an invitation to use
it again. Post interpretive signs at trailheads
to educate the public about the unique and fragile nature of alpine habitat.
1) Design roads with adequate structures to prevent vehicles from leaving the roads and traveling off-road in alpine tundra/grasslands.
2) Maintain buffer zones between alpine tundra/grasslands and mining and other industrial activities, including structures, roads, and support facilities.
3) Restore disturbed areas with native vegetation, prevent grazing by livestock while plants recover, and eliminate the invasion of nonnative plants during the reclamation period.
4) Reclaim areas as soon as possible after activities, such as mining and road building, are completed. This reduces the amount of habitat converted at any one time and speeds up the recovery of the alpine habitat.
5) Emphasize proper environmental engineering of
mine sites and careful evaluation of proposed development of additional roads,
water storage structures, ski facilities, electronic relay stations, and cabin
sites.
1) Where possible, restore or rehabilitate degraded and disturbed sites to native plant communities. The impacts of disturbance on high-elevation lands threaten their important watershed, wildlife habitat, grazing, and recreational values. Revegetation of these disturbances is essential to minimize the consequences of erosion and loss of water quality, and to reestablish stable native ecosystems.
2) Always identify and
address the causes of alpine degradation before starting rehabilitation. Many rehabilitation projects fail without a change
in other management activities, such as grazing or intensive recreation.
3) Tailor specific
rehabilitation efforts to each alpine area.
Physical factors such as geology, microclimate, and elevation will
influence the project’s success.
Conventional techniques of revegetation developed for habitats at lower
elevations are often unsuccessful in disturbed alpine ecosystems. The rigorous climate at high elevations,
coupled with the impacts of disturbance, dictate the use of techniques that
have been designed for the unique conditions in high-elevation areas. Short, cool growing seasons, strong winds,
frequent frosts, and a limited pool of adapted plant species can complicate
revegetation efforts.
4) Determine specific
objectives for each alpine area, and develop a monitoring program to track
whether the objectives are being met.
5) Remove exotic plants that compete with native plant species and do not provide foraging or nesting opportunities for wildlife.
6) Some of the heavily used alpine slopes have been webbed with paths. In spite of established trails, hikers in non-forested areas often take the shortest distance between two points, or simply strike off on their own. Reestablish vegetation by reseeding and replanting, blocking paths off, and covering them with mesh and burlap to prevent erosion. It is necessary to restore their original aspect since any trace of a path is an invitation to use it again.
7) Carefully plan for a complex of vegetation that reflects the diversity of plant species and habitats in the surrounding area. Choose mixtures of plant species that represent different life histories and physiological traits. Typically, grasses are the most widely used group of plants in revegetation, but heavily fertilized swards of high-nutrient adapted grasses often tend to form closed stands that exclude or inhibit the invasion of other species. Include different lifeforms in seeding and planting mixtures to increase species and structural diversity of revegetation communities and enhance rates of successional development. In addition, use seed mixtures consisting of species with many different physiological and ecological characteristics to improve the chances of stand survival in the event of catastrophic events such as insect infestations, disease, or drought.
8) Reseed with local genetic seed stock, if available, and avoid using nonnative plant species that compete with native species.
9) Provide topography similar to the surrounding area to provide microsites that promote a mosaic pattern.
10) Revegetate alpine disturbances in the fall. Timing of revegetation can be extremely important to successful plant establishment. Transplant stock should be hardened to low fall temperatures and should be in a dormant condition during planting. Seeds, transplants, and soil amendments should be applied as late in the growing season as possible so that cold temperatures prevent germination and growth. Severe frost damage to young seedlings and transplanted stock may result if planting is too early. Fall revegetation ensures that seeds and amendments will be in place when conditions are ideal for germination the following spring as snowmelt occurs. Fall seeding and planting can usually be accomplished when conditions are relatively dry and when the soil can be worked most easily.
11) Avoid revegetating alpine disturbances in the spring or summer. Most high-elevation areas remain inaccessible in the spring until large snowdrifts melt. By the time access and site conditions are suitable, the optimum conditions for seed germination and seedling development may be past.
1) Establish public education goals and
implement programs to inform users of public lands and owners of private lands
of the value, sensitivity, and importance of alpine tundra/grasslands to
resident and Neotropical migratory birds and other species. This could range anywhere from interpretive
signs on public lands, to distribution of Best Management Practices to
landowners, to presentations at local grade schools, etc.
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